High-tension spark amplifying means



June 18, 1929. p STEWART 7 1,717,472

HIGH TENSION SPARK AMPLIFYJiNG MEANS Filed Dec. 6, 1926 INVENTOR Pain-25am afliewart Q @31 ATTORNEY Patented June 18, 1929. t

PATTERSON O. STEWART, OF NEW YORK, N. Y.

HIGH-TENSION SPARK AMPLIFYING MEANS.

Application filed December 6, 1926. Serial No. 152,994.

My present invention relates to an improvement in spark amplifying means for use in high tension ignition systems in caloric engines, and to provide an amplifying conductor of improved form to be directly connected in series with a spark plug.

Among the various advantages in my structure, l have provided means for varying the spacing between the associated plates or elements of the gap-pile, at will. In addition thereto means are provided whereby the plates are prevented from approaching each other more than a predetermined minimum, so that any desired distance, within limits, between the plates may be made to increase or decrease the air gap therebetween and hold the same, as desire Certain features of novel construction in the means of attachment will also be noted, as well as structural assembly.

Obvious modifications of my device may be made without departing from the spirit of the herein disclosure or the scope of the claims.

In the drawings, Fig. 1 is a longitudinal sectional view of my device, disclosing details and mode of attachment to a spark plug terminal;

Fig. 2 is a side view thereof;

ig. 3 is a side view of the threaded cap stud;

Fig. 4 is a plan view thereof;

Fig. 5 is a perspective view of one of the solid insulator elements;

Fig. 6 is a perspective view of one of the compressible, elastic insulators;

Fig. 7 is a perspective view of one of the gap plates;

Fig. 8 is a longitudinal sectional view'of a modification Fig. 9 is a similar view showing the device compressed; and

Fig. 10 is a detail and diagrammatical view of one of the gap plates.

My device comprises, essentially an outer tubular dielectric casing 1, preferably cylindrical, and of suitable heat resisting capabilities and has a shouldered, metallic bottom closing cap 2 threadedly engaged at the bottob thereof in a firm manner. This cap is provided with a series of alined progressively smaller threaded bores 3 and 4, respectively, which are central of the cap and are intended to permit the fitting of the device to the varysimilar in ing threaded terminal stems '5 of any spark plug 6, fragmentarily shown in Fig. 1.

The upper end of the casing 1 is provided 7 with an outer integral collar 6. The bottom of this collar has the conformation of a portion of a square'compound thread, thus formng two oppositely located inclined shoultiers 7 and 8, as shown in Fig. 2. The collar 6 is en aged on this threaded lower side by a metallic cap 9 which covers the upper end of the casing 1. The cap is provided with a pair of inbent inclined lugs 10 and 11, which bear on the inclined shoulders 7 and 8. A cap stud 12, having a threaded stem 13, forms an outer extension terminal for the device and the spark plug and protrudes through a central opening in cap 9 as shown in Fig. 1. To the stem 13 there is attached a cable C from a source of current. The cap stud 12 has a disc-like lower portion, of such a size that it is capable of sliding into and within the bore of the casing 1.

Between the conductive bottom cap 2 which is of metal and the above noted disc-like portion of the cap stud 12, there is centrally arranged a. series of superimposed metallic plate members 14 of all equal thickness. In-- terposed between each of these members there I v are located insulator discs 15 made of dielectric material, such as mica.

These discs are preferably of annular or ring-like form.

These annular insulators thin in comparison with the metallic members 14 are incompressible and are allof the same thickness.

Between each insulator 15 and surrounding each plate 14 is a resilient rubber annulus or separator 16, which is of a dimension in thickness, that will support disks 15 and their plates 14, at a maximum distance of separation, the separators 16 all being of the same thickness.

Rotation of the top cap 9, compresses these rubber separators 16 and drives the entire assembly together, till the lates, let contact with the mica disks 15. Tlius minimum or maximum arc gaps of any desired dimension are obtained between the elements of the gap pile.

In the modification shown in two positions, maximum opening, Fig. 8 and minimum opening, Fi 9, the structural elements are function, and difi'er slightly in structure, therefore the same indices are utilized to represent the similar acting structural somewhat distant inwardly elements. The difl'erence herein lies in the thicker dielectric annular disks 15, all of the same thickness, which carry the plates 14, and the said plates being provided with an annular disk receiving seat S onto which the disks 15 are forced, to register the plates and disks together and to firmly position the plates 14: against movement by vibration and jar at all adjusted positions in the action of compression or release heretofore described. The thicker disks 15 in these last two figures permit the use of other moldable forms of dielectric material, less friable than mica, and therefore longer lived, in the action of compression or release heretofore described.

Referring to Fig. 10, it will be noted that the under part ofthe plate 14 is beveled inwardly and downwardly as at X, so that the distance, as XZ, between the top line of the bevel of the plate, adjacent to the dielectric 15, Fig. 8, and the upper surface of the next underlying plate 1 1 is greater than the dis-.

tance as, ,/-2, from the bottom line of the plate 14 to the top line of the next underlying plate 14, the intention being to cause the current to jump the gap between the plates 14 from the edge of the dielectric 15 which is disposed at the sides of the plates and whereby charring or burning of the dielectric by the heat of the arc is avoided.

It is presumed that in the manufacture of this device the resilient members 16 are to be inserted between each and every insulating disk 15 but, if for any reason, should they be removed or left out the device would still be operable and function partly as long as one or more of the resilient members were in place. i I

The operation of the device is obvious from the description. The gap varying action of the elements in this device permit the varying of the voltage of the initial discharge of ourrent, from a predetermined minimum to a predetermined maximum, through any spark plug it may be used with and to do so without disconnecting any wires, the use of any tools or any special skill or knowledge. As is well known, an oil "fouled or carbonized spark plug requires a higher initial voltage to fire than a clean plug and as is also known two or more small. gaps are better than a single large one and as disclosed the fast acting compound screw action of my device permits any adjustment needed to be easily and quickly made.

From the foregoing, and the attached drawings, one might confuse this device with a quenched spark gap such as is disclosed in United States patent issued to A. Press, No. 1,296,006 of March 4, 1919, but I wish to disclaim, for my present invention, the ability to produce a non-vaporizing discharge at the spark plug points and to state that the sectional electrode or gap pile should have, at

all times, an extended surface area of less than means associated with said electrodes to s1- multaneously vary the distance separating said electrodes between predetermined limits, limiting means formed of insulating material assocated with said electrodes determining the minimum spacing of said gaps, a casing of insulating material housing said electrodes meansincorpor'ated therein to limit the maximum spacing of said gaps, said gaps, in conjunction with other resistances in series with them, tending to control the initial voltage of the current flowing in the ignition system.

2. A gap-pile for the purpose described, comprising a plurality of spaced conductive elements, a plurality of insulators of prede termined thickness therebetween and compressible spacing elements associated therewith substantially as described.

3. A gap-pile plate for the ignition system of internal combustion engines, comprising a conductive annular disk having an annular flange portion, a seat portion suitable to be received in and retained by an insulating ring and a sparking portion of smaller diameter than said seat portion.

4. A gap pile for the purpose described comprising a plurality of spaced conductive elements, a plurality of insulators of predetermined thickness between said elements, compressible spacing elements interposed between the insulators for holding them in spaced relation, and means for compressing tie spacing elements toward each other for adjusting the distance between the conductive elements.

Signed at New York. in the county of New York and State of New York this 1th day of December, A. D. 1926.

PATTERSUN O. STEWART. 

